Pressure-regulated air-valve.



PATENTED OCT. 16, 1906.

Z. G. BREWSTER.

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PRESSURE REGULATED AIR VALVE.

APPLICATION FILED JUNE 20. 1905.

ZENO (J; BREWSTER, OF OXFORD, NEW YORK.

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Specification er Letters Patent.

Application filed June 20,1905;

Patented oct. 16, 1906. Serial No. 266,184.

To alZ whom, it may concern;

Be it known that I, ZENo O. BREwsrEn, a

I citizen of the United States, and a resident of Oxford, in the county of Ohenango and State of New York, have invented certain new and useful Improvements in PressureeRegulated Air Valves for Air-Compressors, of which the following is a specification.

My invention relates to a valve for opening and closing the intake pipe of air-compressing apparatus, which valve is in turn controlled by the pressure in the receiver, service-pipe, or other container of the air being compressed.

It is quite usual to employ the pressure of municipal or other water system to actuate hydraulic air-compressors for developing airpressure for various purposes, and for many uses to which such air-pressure is applied it is very desirable to maintain a constant pressure and to employ means which will stop and start the action of the hydraulic aircompressor automatically as the pressure of air in a stora e-receptacle reaches or falls below the pre etermined degree. Automatic devices for this purpose have usually been in the nature of valves controlled by a pressurediaphragm and made to open and close the water supply of the h. 'draulic air compressor; but it has never een practicable to maintain'the air compression constant with an automatic valve applied to the water-sup ply, owing to the comparatively large and variable service-pressure to be controlled.

The objects of my present invention are to provide a system of control and a novel construction of automatic valve employed there= in whereby a predetermined degree of compression developed in a storagereceptacle by a hydraulic compressor may not only be maintained with great accuracy, but very slight changes in such pressure will be effective to actuate the automatic valve regardless of changes "in the servicewatenpressure.

In carrying out my invention I operate wholly upon the air-intake of thehydranlic compressor in controlling the action of the same, my system of control depending upon the fact that if the air-intake is closed the water cannot gravitate from the otherwise tight compression-chamber, and the pump or compressor ceases with the last pulsation that brings the pressure to the predeterminedde'gree. Inasmuch as I am dealing with air at normal atmospheric pressure in arresting the compressing operation instead of with the varying pressure of the water in the service-pipe, it follows that I can operate the automatic valve with substantial balance between the pressure on the diaphragm that closes the valveand the spring that opens it, so that the slightest overbalance in either direction by reduced or increased reservoirpressure is followed by immediate response of the valve to start or arrest the compres'sor, and consequently the predetermined degree of compression will be maintained with great accuracy, nor will this result ,be affected in any way by other influences, since the unchanging normal atmospheric pressure alone can affect the valve. duce the work of cutting ofl its inlet end is reduced thin edge, against which a flat valve-packing (preferably of rubber to enable it to contact all around) is seated by the diaphragm when the pressure is full and from which the valvepacking is unseated by spring pressure when the pressure falls.

My invention will be fully understood upon reference to the accompanying drawings, in which Figure 1 is a general view of a hydraulic air compressing and storing apparatus to which my present invention is applied. Fig; 2 is a longitudinal axial section of the presthe air=intake, to a comparatively To further re-;

sure-controlled air-valve, and Fig. 3' is a detail View.

1 represents a container or receptacle for receiving and holding air under pressure.

2 represents a hydraulic air compressor of known construction which contains a con trolling-float 3, water-discharge pipe 4, water-inlet 5 air-intake 6 with a check-valve 7, and air-discharge pipe 8 with a .checkwalve 9.' As water runs out of the pump 2 and creates a vacuum air enters through pipe 6 under external atmospheric pressure. When float 3 settles to a predetermined point, the waterdischarge 4 is closed, inlet-pipe 5 is opened, and the pump again fills with water, holding check-valve 7 closed and forcing the contained air out through pipe 8 into reservoir 1. When the air is practically discharged and float 3 has reached its upper limit, supply-pipe 5 is closed and dischargepipe 4 is opened, the water again discharges by gravity, and a new charge of air enters through pipe 6, check-valve 9 remaining closed under back pressure from the reservoir. The float, having thus again descend= ed, again shifts the water-valves, and the previously-described pumping action is repeated.

My present invention operates upon the principle that if the air-intake 6 is closed the water will not gravitate out of 'the tight chamber of pump 2, and consequently the pumping action will cease under the last impulse of the incoming water after the pressure in the reservoir reachesa certain degree. 1 One feature of my invention therefore consists in applying to the intakeof an air forcing and pumping apparatus a cut-off valve operated automatically by the pressure of the'air being supplied for consumption, so as to open the intake when the pressure falls below a given degree and close said intake when the pressure reaches the desired point.

In order to accomplish the above-named object, I have provided a novel construction OffilltOHlWtlC valve 10, supported in proper relation to the inlet end of the intake 6 and connected by a pipe 11 with the supply-pipe or a reservoir or other container which is being supplied with air or connected with a service-pipe into which the air is being forced.

The construction of the automatic valve 10 will be best understood upon reference to Figs. 2 and 3, wherein pipe 6 has supported in suitable relation to its open end an expansible diaphragm 12, secured over an expansion-chamber 13, which has a connection, such as pipe 11, through which it is subjected to control of the air-pressure to be regulated.

Diaphragm 12 is suitably loaded by a known means to hold it away from the end of pipe 6 whenever pressure in the chamber 13 falls below a predetermined degree, either equal or proportional to the pressure it is desired to maintain in the reservoirthat is to say, it is equal to such pressure if pipe 11 communicates directly with the reservoir, but is proportional to the pressure in the reservoir if a reduction-valve or other means is introduced in said pipe. In cases where very high pressures are being stored a reduction-valve can be used to advantage.

The means employed for loading the diaphragm 12 is preferably a rigid'disk 14, rest ing above said diaphragm and formingthe abutment for one end of each of a pair of springs 15, which abut at their opposite ends against a follower 16. Follower 16, as well as the springs 15, are guided by rods 17, projecting rigidly from the walls of chamber 13 and secured at their upper ends to a yoke 18, which affords convenient means for supporting the entire valve on the pipe 6. The diaphragm 12 is adjustable relatively to the pipe 6 for varying the opening at the end of said pipe by having yoke 18 threaded on the pipe 6 and held to its adjustment by am-nut 19. This adjustment provides for proximately determining the degree of pressure required beneath the diaphragm to closethe intake-pipe. For the purpose of predetermming th1s pressure w1th accuracy I vary the load imposed'by springs 15 upon the disk 14, "and consequently upon the diaphragm 12, by providing a milled hand-nut 20, threaded on the pipe 6 above the follower 1 6 and adapted to depress the follower and compress the springs 15 to any desired degree. balance the valve between the diaphragmpressure on one side and spring-pressure on the other as to cause it to close the intake immediately upon obtaining the desired pressure in the reservoir-and to cause it to open the intake under the slightest reduction from said pressure, so that the pump may again compress the air to the number of pounds required. The fact that I am dealing with so light a medium as the atmosphere at normal pressure in controlling-the ump enables me to work with a substantia balance between loads on opposite sides of the valve and obtain such delicacy of operation. Under these conditions I can with slight adustments of the hand-nut change the degree of pressure that will be maintained at will. In order to reduce wear upon the diaphragm 12, and thus avoid puncturing it and putting the device out of action, as well as wasting pressure in the reservoir in the event'of such mishap, a packing 21 isinterposed between 'the diaphragm and the disk 14. This packing is preferably of flexible material, such as rubber or the like, in order that it may seat evenly against the end of pipe 6, which is reduced to a thin edge to facilitate seating and to reduce the work required to make a tight closure. As shown in Fig. 3, the packing 21 fits upon the guide-rods 17 by peripheral notches. It thus becomes very convenient to raise the disk 14 and remove a badly-worn packing 21 and to quickly replace it by a new packing without appreciably interrupting the automatic control of the pump.

While I have disclosed more or less in detail the specific construction of valve that I have found to be effective for the purpose stated, I desire it to be understood that I do not limit myself to the particular details herein disclosed, as it is obvious that many changes might be made without departing. from the scope of my invention. I also de sire it to be understood that my invention 1s not limited in its application to the particular type of hydraulic air-compressor herein selected for purposes of illustration. The device is obviously applicable to any type of air-forcing mechanism where an interruption of the air-intake will cause temporary cessation of the operation.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

1. In an air-compressor, the combination of an air-intake pipe having one end open toward the atmosphere, a valve adapted to move toward and from the open end of the Iso intake-pipe and having one side subject to the pressure of the atmosphere, springs acting on the valve in conjunction with the atmospheric pressure, and a connection whereby the other side of the valve is subject to the pressure of the compressed air.

2. In an automatic valve, the combination of the air-intake pipe, the pressure chamber and diaphragm, the rods projecting from the pressure-chamber, the springs surrounding the rods for holding the diaphragm away from the pipe, and the packing interposed between the diaphragm and pipe and releasably engaging the rods by peripheral notches. 3. In an automatic valve, the combination of the air-intake pipe, the yoke screwed there- 

